Dr. Yogi Nagai joined LSB in March 1996 to work on the project with us. The project studies intracerebral blood flow velocity and resistance, and carotid blood flow velocity using doppler ultrasonography in BLSA participants. The goal is to determine how these factors, which are associated with cerebrovascular diseases, change with age. It complements the studies of Drs. Lakatta and Fleg in the Laboratory of Cardiovascular Disease on arterial stiffness, by exploring the effects of stiffness on an end organ (the brain). Two abstracts have been prepared. The first for the Annual Meeting of the Gerontological Society of America is titled Aging and Intimal-Medial-Thickness(IMT) of Common Carotid Artery(CCA)-Ultrasonographical Assessment demonstrated that IMT increases with age concomitant with CCA dilatation, elevation of systolic blood pressure and differently by gender. The second abstract is for the American Heart Association Meeting and titled Stiffness of Common Carotid Artery(CCA) -Assessment by two different methods: ultrasonography and applanation tonometry. Augmentation index (AGI)(r=.38, p=.000) and Ep increased with age, DC(r=-.43, p=.000) and CC(r=-.25, p=.021) decreased with age, while YM did not change with age. AGI did not significantly correlate with the ultrasonographical indices, though Ep and YM had significant correlations with AGI after controlling for age (r2=.23, r=.18, respectively). AGI and ultrasonographical indices of elasticity express different characteristic of vascular stiffness. The findings suggest that both the AGI and ultrasonographic measurements should give a better understanding of arterial changes with age, than either measurement alone.